1. Field of the Invention
The invention relates to a method and a device for producing folded printed products such as, for example, newspapers or brochures, wherein by means of at least one digital printing machine a paper web is sequentially printed, respectively, and, subsequently, this paper web is cut or further processed into full-size sheets or into web sections, each divided into at least four pages, for printed products with a multiple of four pages, wherein the full-size sheets or web sections are folded, the folded full-size sheets or web sections are collected, and the collected, folded full-size sheets or web sections are stitched.
2. Description of the Related Art
Devices of the aforementioned kind are known, for example, from European patent application EP 1 005 984 A1. In this method, the printed products are received as a printed paper web from an electronic printer, for example, a laser printer, and are cut by means of a cutting device to individual full-size sheets. The sheets are then provided in the transport direction with one or two scoring lines and are then folded so as to form a fold. The folded printed products are then collected to form a saddle-shaped stack which is stitched. In order for the spine of the printed product to be as narrow as possible, the spine is pressed.
European patent application EP 0 992 365 A1 discloses a method wherein the printed products are also individually folded before being collected. The folded printed products are stacked, stitched, and cut.
European patent document EP 0 869 092 of the applicant describes a method for producing printed products wherein the webs of paper are printed according to a preselected page sequence and are cut to individual sheets. The cut sheets are rotated with respect to their position by 90° and then fed for further processing to feeders 11.
The sheet-wise folding of the sheets before collecting them has a decisive advantage in that a good folding quality is achieved and even multi-page brochures with a comparatively narrow spine can be produced. In the described methods and the corresponding processing arrangements or device there is the difficulty that even comparatively short disruptions in the processing sequence, for example, during stitching, result in disruptions and negative feedback in regard to the printing machine.